1. Technical Field
The present invention relates to an apparatus and a system for automatically tracking data speed, more particularly to an apparatus and a system that enables a receiving apparatus to recover a clock and input data without a reference clock.
2. Description of the Related Art
An apparatus for automatic data speed tracking is an apparatus for recovering a clock without a reference clock or a reference clock transmission line. The performance, transmission speed, complexity, etc., of the apparatus may vary according to the recovery method used.
One of the automatic data speed tracking methods most used in the related art is the clock embedded method, in which a clock is sent in regular intervals instead of data, so that a clock matching the data speed can be recovered at the receiving end by using the clock transmitted at regular intervals.
This method provides the advantage that the transmission speed of the data can be found easily, but since a clock is sent at regular intervals instead of data, the transmission speed is limited.
The number of bits added thus is referred to as overhead, and several methods for reducing overhead have been developed.
Another method of automatically tracking data speed is to recover a clock by finding the regularity of the data. With this method also, however, transition information is required for finding the regularity, so that a method such as 8B10B encoding is used which adds overhead. Moreover, this method may result in a large area and high power consumption for finding the regularity.